Using object or embed tags, it was possible to frame other websites, even if they disallowed framing using the X-Frame-Options header. This vulnerability affects Thunderbird < 78 and Firefox < 78.0.2.
https://bugzilla.mozilla.org/show_bug.cgi?id=1644076
Source: MITRE
Published: 2020-08-10
Updated: 2020-08-12
Type: CWE-1021
Base Score: 4.3
Vector: AV:N/AC:M/Au:N/C:N/I:P/A:N
Impact Score: 2.9
Exploitability Score: 8.6
Severity: MEDIUM
Base Score: 6.5
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
Impact Score: 3.6
Exploitability Score: 2.8
Severity: MEDIUM